Numerous types of cancer exist. Among these there can be mentioned in particular neuroblastoma.
Neuroblastoma is a relatively rare cancer of the sympathetic nervous system which mainly affects children. Neuroblastoma is a malignant tumour which is most common in children, developing from progenitor cells of the neural crest having to colonize the adrenal medulla and the sympathetic ganglions. Neuroblastoma is usually found in babies and young children. Approximately 96% of cases of neuroblastomas appear before the age of 10 years. The disease generally appears in the adrenal medulla gland or in other sites of the sympathetic nervous tissue, the most common site being in the abdomen in the vicinity of the adrenal gland. Neuroblastomas can also be found in the chest, neck or pelvis. Patients suffering from a neuroblastoma type cancer have a high probability of detection. Frequent symptoms of neuroblastomas are pressure caused by the tumour or bone pain. Neuroblastomas can also compress the spinal cord causing paralysis. Cases of fevers, anaemia, or high blood pressure can also be noted.
The treatment of neuroblastoma is based on a multidisciplinary approach essentially combining surgery, radiotherapy and chemotherapy. Among the treatments known at present, the treatments using cyclophosphamide, doxorubicin, etoposide, platinum salts or vincristine can be mentioned.
Among the cancers, leukaemias can also be mentioned.
The term leukaemia refers to a set of cancers affecting the blood. The average adult possesses approximately five liters of blood, the role of which is to provide nutritive elements, oxygenation and the evacuation of waste. Blood is composed of erythrocytes, leukocytes, platelets and plasma. Leukocytes aid in combating infection. Blood platelets form clots preventing the loss of blood during injuries and haemorrhages. Approximately 55% of the blood is constituted by plasma, a light straw coloured liquid which contains the blood cells and the platelets, and transports the food originating from digestion and the hormones originating from the glands into the organism. As indicated, the leukocytes are responsible for a defence mechanism. There are two main types of leukocytes, the lymphocytes and the monocytes. There are two types of lymphocytes, the B lymphocytes, involved in the production of antibodies, and the T lymphocytes. The T lymphocytes are also divided into 3 groups: the inflammatory T cells, which recruit macrophages and neutrophils at the site of the infection or any other damaged tissue; the cytotoxic T lymphocytes, which kill the viruses which have infected cells; and T-helper cells, which increase the production of the antibodies by the B cells. Acute lymphoblastic leukaemia is the most common leukaemia in children. This is a cancer of the leukocytes, specifically of the lymphocytes. The cancerous leukaemia cells are blood cells which no longer function normally. As a result, the leukocytes cannot help the body to combat infections. For this reason, children with an acute lymphoblastic leukaemia frequently have infections and have fevers. Depending on the number of abnormal cells and their location, patients with leukaemia can have a certain number of symptoms. Children with acute lymphoblastic leukaemia frequently have small quantities of erythrocytes and healthy platelets. As a consequence, there are not enough erythrocytes to carry oxygen to the organs, which results in anaemia, with patients possibly seeming pale with a sensation of weakness and fatigue. When there are not enough platelets, patients bleed and are easily injured. Certain common symptoms of acute lymphoblastic leukaemia include: fever; fatigue; frequent infections; pallor; easy bleeding or bruising; small reds spots (called petechiae) under the skin; and/or pain in the bones or joints.
Leukaemia treatments known at present are inter alia the treatments using Ara-C, Idarubicin, Daunorubicin, Melphalan or Busulphan.
Among the cancers, prostate cancers can also be mentioned.
Prostate cancer is a common cancer exclusively affecting men. The prostate forms part of the male reproductive system. A healthy prostate is the size of a chestnut. The prostate is an organ situated immediately below the bladder, behind the symphysis pubis and in front of the rectum. It surrounds the ureter, the duct evacuating urine, over 3 to 4 cm. The prostate is a gland which produces part of the seminal liquid. An enlarged prostate will squeeze the ureter posing urinary problems by slowing down or stopping the flow of the urine from the bladder to the penis. More than 70% of all prostate cancers are diagnosed in men generally above the age of 65 years. Although the etiology of prostate cancer is unknown, the risk factors include the environment, genetics and family history. The mortality rate for prostate cancer is at least twice as high in Afro-American men as in Caucasian men. Because of the additional risk, earlier screening for prostate cancer is recommended for Afro-American men. According to the American Cancer Society, men aged 50 years and more, and those above the age of 45 years who are in the high-risk groups, such as Afro-American men and men with a family history of prostate cancer, should have a blood analysis to screen for the prostate specific antigen (PSA) and a rectal examination each year. The symptoms of prostate cancer generally include: urinary problems; an inability to urinate, or difficulty in starting or stopping the flow of urine; the need to urinate frequently, particularly at night; a weak or interrupted flow of urine; pain or burning during micturition; difficulty in achieving an erection; the presence of blood in the urine or sperm; and frequent pain in the lower back, hips or thighs.
The treatments known at present for treating prostate cancer are inter alia the use of a peptide, triptorelin, which is an analogue of the LHRH (Luteinizing Hormone Releasing Hormone), used to the extent that the growth of tumour cells is under androgenic hormonal control. Very frequently, after a long period of treatment with LHRH analogues, the tumour cells lose their sensitivity to hormonal control and then become hormone-resistant.
Chemotherapy is preferably used in prostate cancer when the latter has developed with an extraprostatic extension and it no longer responds to hormonal treatment. It comprises the use of products or mixtures of products such as docetaxel, paclitaxel, estramustine/docetaxel, estramustine/etoposide, estramustine/vinblastine, and estramustine/paclitaxel.
The treatment of cancers, such as for example neuroblastoma, leukaemia, prostate cancer, breast cancer, melanoma or colorectal cancer can be local or systemic. The local treatments, such as surgery and radiation, affect the cancerous cells of the tumour and the sector close to the latter. The systemic treatments, such as chemotherapy, hormonal therapy, and biological therapy, are conveyed by the blood circulation, reaching cancerous cells everywhere in the body, but also healthy cells causing many undesirable effects.